/mandos/trunk : revision 532

9

* "browse_callback", and parts of "main".

10

*

11

* Everything else is

12

13

12

13

14

*

15

* This program is free software: you can redistribute it and/or

16

* modify it under the terms of the GNU General Public License as

32

/* Needed by GPGME, specifically gpgme_data_seek() */

33

#ifndef _LARGEFILE_SOURCE

34

#define _LARGEFILE_SOURCE

35

#endif /* not _LARGEFILE_SOURCE */

35

#endif

36

#ifndef _FILE_OFFSET_BITS

37

#define _FILE_OFFSET_BITS 64

38

#endif /* not _FILE_OFFSET_BITS */

38

#endif

39

40

#define _GNU_SOURCE /* TEMP_FAILURE_RETRY(), asprintf() */

41

42

#include <stdio.h> /* fprintf(), stderr, fwrite(),

43

stdout, ferror() */

44

#include <stdint.h> /* uint16_t, uint32_t, intptr_t */

43

stdout, ferror(), remove() */

44

#include <stdint.h> /* uint16_t, uint32_t */

45

#include <stddef.h> /* NULL, size_t, ssize_t */

46

#include <stdlib.h> /* free(), EXIT_SUCCESS, srand(),

47

strtof(), abort() */

48

#include <stdbool.h> /* bool, false, true */

49

#include <string.h> /* strcmp(), strlen(), strerror(),

50

asprintf(), strncpy() */

49

#include <string.h> /* memset(), strcmp(), strlen(),

50

strerror(), asprintf(), strcpy() */

51

#include <sys/ioctl.h> /* ioctl */

52

#include <sys/types.h> /* socket(), inet_pton(), sockaddr,

53

sockaddr_in6, PF_INET6,

55

opendir(), DIR */

56

#include <sys/stat.h> /* open(), S_ISREG */

57

#include <sys/socket.h> /* socket(), struct sockaddr_in6,

58

inet_pton(), connect(),

59

getnameinfo() */

60

#include <fcntl.h> /* open(), unlinkat(), AT_REMOVEDIR */

58

inet_pton(), connect() */

59

#include <fcntl.h> /* open() */

61

60

#include <dirent.h> /* opendir(), struct dirent, readdir()

62

61

*/

63

62

#include <inttypes.h> /* PRIu16, PRIdMAX, intmax_t,

64

63

strtoimax() */

65

#include <errno.h> /* perror(), errno, EINTR, EINVAL,

66

EAI_SYSTEM, ENETUNREACH,

67

EHOSTUNREACH, ECONNREFUSED, EPROTO,

68

EIO, ENOENT, ENXIO, ENOMEM, EISDIR,

69

ENOTEMPTY,

64

#include <assert.h> /* assert() */

65

#include <errno.h> /* perror(), errno,

70

66

program_invocation_short_name */

71

67

#include <time.h> /* nanosleep(), time(), sleep() */

72

68

#include <net/if.h> /* ioctl, ifreq, SIOCGIFFLAGS, IFF_UP,

77

73

*/

78

74

#include <unistd.h> /* close(), SEEK_SET, off_t, write(),

79

75

getuid(), getgid(), seteuid(),

80

setgid(), pause(), _exit(),

81

unlinkat() */

82

#include <arpa/inet.h> /* inet_pton(), htons() */

76

setgid(), pause(), _exit() */

77

#include <arpa/inet.h> /* inet_pton(), htons, inet_ntop() */

83

78

#include <iso646.h> /* not, or, and */

84

79

#include <argp.h> /* struct argp_option, error_t, struct

85

80

argp_state, struct argp,

93

88

#include <sys/wait.h> /* waitpid(), WIFEXITED(),

94

89

WEXITSTATUS(), WTERMSIG() */

95

90

#include <grp.h> /* setgroups() */

96

#include <argz.h> /* argz_add_sep(), argz_next(),

97

argz_delete(), argz_append(),

98

argz_stringify(), argz_add(),

99

argz_count() */

100

#include <netdb.h> /* getnameinfo(), NI_NUMERICHOST,

101

EAI_SYSTEM, gai_strerror() */

102

91

103

92

#ifdef __linux__

104

93

#include <sys/klog.h> /* klogctl() */

146

135

static const char sys_class_net[] = "/sys/class/net";

147

136

char *connect_to = NULL;

148

137

const char *hookdir = HOOKDIR;

149

int hookdir_fd = -1;

150

uid_t uid = 65534;

151

gid_t gid = 65534;

152

138

153

139

/* Doubly linked list that need to be circularly linked when used */

154

140

typedef struct server{

155

141

const char *ip;

156

in_port_t port;

142

uint16_t port;

157

143

AvahiIfIndex if_index;

158

144

int af;

159

145

struct timespec last_seen;

163

149

164

150

/* Used for passing in values through the Avahi callback functions */

165

151

typedef struct {

152

AvahiSimplePoll *simple_poll;

166

153

AvahiServer *server;

167

154

gnutls_certificate_credentials_t cred;

168

155

unsigned int dh_bits;

170

157

const char *priority;

171

158

gpgme_ctx_t ctx;

172

159

server *current_server;

173

char *interfaces;

174

size_t interfaces_size;

175

160

} mandos_context;

176

161

177

/* global so signal handler can reach it*/

178

AvahiSimplePoll *simple_poll;

162

/* global context so signal handler can reach it*/

163

mandos_context mc = { .simple_poll = NULL, .server = NULL,

164

.dh_bits = 1024, .priority = "SECURE256"

165

":!CTYPE-X.509:+CTYPE-OPENPGP",

166

.current_server = NULL };

179

167

180

168

sig_atomic_t quit_now = 0;

181

169

int signal_received = 0;

182

170

183

171

/* Function to use when printing errors */

184

172

void perror_plus(const char *print_text){

185

int e = errno;

186

173

fprintf(stderr, "Mandos plugin %s: ",

187

174

program_invocation_short_name);

188

errno = e;

189

175

perror(print_text);

190

176

}

191

177

192

__attribute__((format (gnu_printf, 2, 3), nonnull))

178

__attribute__((format (gnu_printf, 2, 3)))

193

179

int fprintf_plus(FILE *stream, const char *format, ...){

194

180

va_list ap;

195

181

va_start (ap, format);

196

182

197

183

TEMP_FAILURE_RETRY(fprintf(stream, "Mandos plugin %s: ",

198

184

program_invocation_short_name));

199

return (int)TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

185

return TEMP_FAILURE_RETRY(vfprintf(stream, format, ap));

200

186

}

201

187

202

188

/*

204

190

* bytes. "buffer_capacity" is how much is currently allocated,

205

191

* "buffer_length" is how much is already used.

206

192

*/

207

__attribute__((nonnull, warn_unused_result))

208

193

size_t incbuffer(char **buffer, size_t buffer_length,

209

194

size_t buffer_capacity){

210

195

if(buffer_length + BUFFER_SIZE > buffer_capacity){

211

char *new_buf = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

212

if(new_buf == NULL){

213

int old_errno = errno;

214

free(*buffer);

215

errno = old_errno;

216

*buffer = NULL;

196

*buffer = realloc(*buffer, buffer_capacity + BUFFER_SIZE);

197

if(buffer == NULL){

217

198

return 0;

218

199

}

219

*buffer = new_buf;

220

200

buffer_capacity += BUFFER_SIZE;

221

201

}

222

202

return buffer_capacity;

223

203

}

224

204

225

205

/* Add server to set of servers to retry periodically */

226

__attribute__((nonnull, warn_unused_result))

227

bool add_server(const char *ip, in_port_t port, AvahiIfIndex if_index,

228

int af, server **current_server){

206

bool add_server(const char *ip, uint16_t port, AvahiIfIndex if_index,

207

int af){

229

208

int ret;

230

209

server *new_server = malloc(sizeof(server));

231

210

if(new_server == NULL){

238

217

.af = af };

239

218

if(new_server->ip == NULL){

240

219

perror_plus("strdup");

241

free(new_server);

242

return false;

243

}

244

ret = clock_gettime(CLOCK_MONOTONIC, &(new_server->last_seen));

245

if(ret == -1){

246

perror_plus("clock_gettime");

247

#ifdef __GNUC__

248

#pragma GCC diagnostic push

249

#pragma GCC diagnostic ignored "-Wcast-qual"

250

#endif

251

free((char *)(new_server->ip));

252

#ifdef __GNUC__

253

#pragma GCC diagnostic pop

254

#endif

255

free(new_server);

256

220

return false;

257

221

}

258

222

/* Special case of first server */

259

if(*current_server == NULL){

223

if (mc.current_server == NULL){

260

224

new_server->next = new_server;

261

225

new_server->prev = new_server;

262

*current_server = new_server;

226

mc.current_server = new_server;

227

/* Place the new server last in the list */

263

228

} else {

264

/* Place the new server last in the list */

265

new_server->next = *current_server;

266

new_server->prev = (*current_server)->prev;

229

new_server->next = mc.current_server;

230

new_server->prev = mc.current_server->prev;

267

231

new_server->prev->next = new_server;

268

(*current_server)->prev = new_server;

232

mc.current_server->prev = new_server;

233

}

234

ret = clock_gettime(CLOCK_MONOTONIC, &mc.current_server->last_seen);

235

if(ret == -1){

236

perror_plus("clock_gettime");

237

return false;

269

238

}

270

239

return true;

271

240

}

273

242

/*

274

243

* Initialize GPGME.

275

244

*/

276

__attribute__((nonnull, warn_unused_result))

277

static bool init_gpgme(const char * const seckey,

278

const char * const pubkey,

279

const char * const tempdir,

280

mandos_context *mc){

245

static bool init_gpgme(const char *seckey, const char *pubkey,

246

const char *tempdir){

281

247

gpgme_error_t rc;

282

248

gpgme_engine_info_t engine_info;

283

249

250

284

251

/*

285

252

* Helper function to insert pub and seckey to the engine keyring.

286

253

*/

287

bool import_key(const char * const filename){

254

bool import_key(const char *filename){

288

255

int ret;

289

256

int fd;

290

257

gpgme_data_t pgp_data;

302

269

return false;

303

270

}

304

271

305

rc = gpgme_op_import(mc->ctx, pgp_data);

272

rc = gpgme_op_import(mc.ctx, pgp_data);

306

273

if(rc != GPG_ERR_NO_ERROR){

307

274

fprintf_plus(stderr, "bad gpgme_op_import: %s: %s\n",

308

275

gpgme_strsource(rc), gpgme_strerror(rc));

309

276

return false;

310

277

}

311

278

312

ret = close(fd);

279

ret = (int)TEMP_FAILURE_RETRY(close(fd));

313

280

if(ret == -1){

314

281

perror_plus("close");

315

282

}

352

319

}

353

320

354

321

/* Create new GPGME "context" */

355

rc = gpgme_new(&(mc->ctx));

322

rc = gpgme_new(&(mc.ctx));

356

323

if(rc != GPG_ERR_NO_ERROR){

357

324

fprintf_plus(stderr, "Mandos plugin mandos-client: "

358

325

"bad gpgme_new: %s: %s\n", gpgme_strsource(rc),

371

338

* Decrypt OpenPGP data.

372

339

* Returns -1 on error

373

340

*/

374

__attribute__((nonnull, warn_unused_result))

375

341

static ssize_t pgp_packet_decrypt(const char *cryptotext,

376

342

size_t crypto_size,

377

char **plaintext,

378

mandos_context *mc){

343

char **plaintext){

379

344

gpgme_data_t dh_crypto, dh_plain;

380

345

gpgme_error_t rc;

381

346

ssize_t ret;

407

372

408

373

/* Decrypt data from the cryptotext data buffer to the plaintext

409

374

data buffer */

410

rc = gpgme_op_decrypt(mc->ctx, dh_crypto, dh_plain);

375

rc = gpgme_op_decrypt(mc.ctx, dh_crypto, dh_plain);

411

376

if(rc != GPG_ERR_NO_ERROR){

412

377

fprintf_plus(stderr, "bad gpgme_op_decrypt: %s: %s\n",

413

378

gpgme_strsource(rc), gpgme_strerror(rc));

414

379

plaintext_length = -1;

415

380

if(debug){

416

381

gpgme_decrypt_result_t result;

417

result = gpgme_op_decrypt_result(mc->ctx);

382

result = gpgme_op_decrypt_result(mc.ctx);

418

383

if(result == NULL){

419

384

fprintf_plus(stderr, "gpgme_op_decrypt_result failed\n");

420

385

} else {

497

462

return plaintext_length;

498

463

}

499

464

500

__attribute__((warn_unused_result, const))

501

static const char *safe_string(const char *str){

502

if(str == NULL)

503

return "(unknown)";

504

return str;

505

}

506

507

__attribute__((warn_unused_result))

508

static const char *safer_gnutls_strerror(int value){

509

const char *ret = gnutls_strerror(value);

510

return safe_string(ret);

465

static const char * safer_gnutls_strerror(int value){

466

const char *ret = gnutls_strerror(value); /* Spurious warning from

467

-Wunreachable-code */

468

if(ret == NULL)

469

ret = "(unknown)";

470

return ret;

511

471

}

512

472

513

473

/* GnuTLS log function callback */

514

__attribute__((nonnull))

515

474

static void debuggnutls(__attribute__((unused)) int level,

516

475

const char* string){

517

476

fprintf_plus(stderr, "GnuTLS: %s", string);

518

477

}

519

478

520

__attribute__((nonnull(1, 2, 4), warn_unused_result))

521

479

static int init_gnutls_global(const char *pubkeyfilename,

522

const char *seckeyfilename,

523

const char *dhparamsfilename,

524

mandos_context *mc){

480

const char *seckeyfilename){

525

481

int ret;

526

unsigned int uret;

527

482

528

483

if(debug){

529

484

fprintf_plus(stderr, "Initializing GnuTLS\n");

530

485

}

531

486

487

ret = gnutls_global_init();

488

if(ret != GNUTLS_E_SUCCESS){

489

fprintf_plus(stderr, "GnuTLS global_init: %s\n",

490

safer_gnutls_strerror(ret));

491

return -1;

492

}

493

532

494

if(debug){

533

495

/* "Use a log level over 10 to enable all debugging options."

534

496

* - GnuTLS manual

538

500

}

539

501

540

502

/* OpenPGP credentials */

541

ret = gnutls_certificate_allocate_credentials(&mc->cred);

503

ret = gnutls_certificate_allocate_credentials(&mc.cred);

542

504

if(ret != GNUTLS_E_SUCCESS){

543

505

fprintf_plus(stderr, "GnuTLS memory error: %s\n",

544

506

safer_gnutls_strerror(ret));

507

gnutls_global_deinit();

545

508

return -1;

546

509

}

547

510

553

516

}

554

517

555

518

ret = gnutls_certificate_set_openpgp_key_file

556

(mc->cred, pubkeyfilename, seckeyfilename,

519

(mc.cred, pubkeyfilename, seckeyfilename,

557

520

GNUTLS_OPENPGP_FMT_BASE64);

558

521

if(ret != GNUTLS_E_SUCCESS){

559

522

fprintf_plus(stderr,

565

528

}

566

529

567

530

/* GnuTLS server initialization */

568

ret = gnutls_dh_params_init(&mc->dh_params);

531

ret = gnutls_dh_params_init(&mc.dh_params);

569

532

if(ret != GNUTLS_E_SUCCESS){

570

533

fprintf_plus(stderr, "Error in GnuTLS DH parameter"

571

534

" initialization: %s\n",

572

535

safer_gnutls_strerror(ret));

573

536

goto globalfail;

574

537

}

575

/* If a Diffie-Hellman parameters file was given, try to use it */

576

if(dhparamsfilename != NULL){

577

gnutls_datum_t params = { .data = NULL, .size = 0 };

578

do {

579

int dhpfile = open(dhparamsfilename, O_RDONLY);

580

if(dhpfile == -1){

581

perror_plus("open");

582

dhparamsfilename = NULL;

583

break;

584

}

585

size_t params_capacity = 0;

586

while(true){

587

params_capacity = incbuffer((char **)&params.data,

588

(size_t)params.size,

589

(size_t)params_capacity);

590

if(params_capacity == 0){

591

perror_plus("incbuffer");

592

free(params.data);

593

params.data = NULL;

594

dhparamsfilename = NULL;

595

break;

596

}

597

ssize_t bytes_read = read(dhpfile,

598

params.data + params.size,

599

BUFFER_SIZE);

600

/* EOF */

601

if(bytes_read == 0){

602

break;

603

}

604

/* check bytes_read for failure */

605

if(bytes_read < 0){

606

perror_plus("read");

607

free(params.data);

608

params.data = NULL;

609

dhparamsfilename = NULL;

610

break;

611

}

612

params.size += (unsigned int)bytes_read;

613

}

614

if(params.data == NULL){

615

dhparamsfilename = NULL;

616

}

617

if(dhparamsfilename == NULL){

618

break;

619

}

620

ret = gnutls_dh_params_import_pkcs3(mc->dh_params, &params,

621

GNUTLS_X509_FMT_PEM);

622

if(ret != GNUTLS_E_SUCCESS){

623

fprintf_plus(stderr, "Failed to parse DH parameters in file"

624

" \"%s\": %s\n", dhparamsfilename,

625

safer_gnutls_strerror(ret));

626

dhparamsfilename = NULL;

627

}

628

} while(false);

629

}

630

if(dhparamsfilename == NULL){

631

if(mc->dh_bits == 0){

632

/* Find out the optimal number of DH bits */

633

/* Try to read the private key file */

634

gnutls_datum_t buffer = { .data = NULL, .size = 0 };

635

do {

636

int secfile = open(seckeyfilename, O_RDONLY);

637

if(secfile == -1){

638

perror_plus("open");

639

break;

640

}

641

size_t buffer_capacity = 0;

642

while(true){

643

buffer_capacity = incbuffer((char **)&buffer.data,

644

(size_t)buffer.size,

645

(size_t)buffer_capacity);

646

if(buffer_capacity == 0){

647

perror_plus("incbuffer");

648

free(buffer.data);

649

buffer.data = NULL;

650

break;

651

}

652

ssize_t bytes_read = read(secfile,

653

buffer.data + buffer.size,

654

BUFFER_SIZE);

655

/* EOF */

656

if(bytes_read == 0){

657

break;

658

}

659

/* check bytes_read for failure */

660

if(bytes_read < 0){

661

perror_plus("read");

662

free(buffer.data);

663

buffer.data = NULL;

664

break;

665

}

666

buffer.size += (unsigned int)bytes_read;

667

}

668

close(secfile);

669

} while(false);

670

/* If successful, use buffer to parse private key */

671

gnutls_sec_param_t sec_param = GNUTLS_SEC_PARAM_ULTRA;

672

if(buffer.data != NULL){

673

{

674

gnutls_openpgp_privkey_t privkey = NULL;

675

ret = gnutls_openpgp_privkey_init(&privkey);

676

if(ret != GNUTLS_E_SUCCESS){

677

fprintf_plus(stderr, "Error initializing OpenPGP key"

678

" structure: %s",

679

safer_gnutls_strerror(ret));

680

free(buffer.data);

681

buffer.data = NULL;

682

} else {

683

ret = gnutls_openpgp_privkey_import

684

(privkey, &buffer, GNUTLS_OPENPGP_FMT_BASE64, "", 0);

685

if(ret != GNUTLS_E_SUCCESS){

686

fprintf_plus(stderr, "Error importing OpenPGP key : %s",

687

safer_gnutls_strerror(ret));

688

privkey = NULL;

689

}

690

free(buffer.data);

691

buffer.data = NULL;

692

if(privkey != NULL){

693

/* Use private key to suggest an appropriate

694

sec_param */

695

sec_param = gnutls_openpgp_privkey_sec_param(privkey);

696

gnutls_openpgp_privkey_deinit(privkey);

697

if(debug){

698

fprintf_plus(stderr, "This OpenPGP key implies using"

699

" a GnuTLS security parameter \"%s\".\n",

700

safe_string(gnutls_sec_param_get_name

701

(sec_param)));

702

}

703

}

704

}

705

}

706

if(sec_param == GNUTLS_SEC_PARAM_UNKNOWN){

707

/* Err on the side of caution */

708

sec_param = GNUTLS_SEC_PARAM_ULTRA;

709

if(debug){

710

fprintf_plus(stderr, "Falling back to security parameter"

711

" \"%s\"\n",

712

safe_string(gnutls_sec_param_get_name

713

(sec_param)));

714

}

715

}

716

}

717

uret = gnutls_sec_param_to_pk_bits(GNUTLS_PK_DH, sec_param);

718

if(uret != 0){

719

mc->dh_bits = uret;

720

if(debug){

721

fprintf_plus(stderr, "A \"%s\" GnuTLS security parameter"

722

" implies %u DH bits; using that.\n",

723

safe_string(gnutls_sec_param_get_name

724

(sec_param)),

725

mc->dh_bits);

726

}

727

} else {

728

fprintf_plus(stderr, "Failed to get implied number of DH"

729

" bits for security parameter \"%s\"): %s\n",

730

safe_string(gnutls_sec_param_get_name

731

(sec_param)),

732

safer_gnutls_strerror(ret));

733

goto globalfail;

734

}

735

} else if(debug){

736

fprintf_plus(stderr, "DH bits explicitly set to %u\n",

737

mc->dh_bits);

738

}

739

ret = gnutls_dh_params_generate2(mc->dh_params, mc->dh_bits);

740

if(ret != GNUTLS_E_SUCCESS){

741

fprintf_plus(stderr, "Error in GnuTLS prime generation (%u"

742

" bits): %s\n", mc->dh_bits,

743

safer_gnutls_strerror(ret));

744

goto globalfail;

745

}

746

}

747

gnutls_certificate_set_dh_params(mc->cred, mc->dh_params);

538

ret = gnutls_dh_params_generate2(mc.dh_params, mc.dh_bits);

539

if(ret != GNUTLS_E_SUCCESS){

540

fprintf_plus(stderr, "Error in GnuTLS prime generation: %s\n",

541

safer_gnutls_strerror(ret));

542

goto globalfail;

543

}

544

545

gnutls_certificate_set_dh_params(mc.cred, mc.dh_params);

748

546

749

547

return 0;

750

548

751

549

globalfail:

752

550

753

gnutls_certificate_free_credentials(mc->cred);

754

gnutls_dh_params_deinit(mc->dh_params);

551

gnutls_certificate_free_credentials(mc.cred);

552

gnutls_global_deinit();

553

gnutls_dh_params_deinit(mc.dh_params);

755

554

return -1;

756

555

}

757

556

758

__attribute__((nonnull, warn_unused_result))

759

static int init_gnutls_session(gnutls_session_t *session,

760

mandos_context *mc){

557

static int init_gnutls_session(gnutls_session_t *session){

761

558

int ret;

762

559

/* GnuTLS session creation */

763

560

do {

775

572

{

776

573

const char *err;

777

574

do {

778

ret = gnutls_priority_set_direct(*session, mc->priority, &err);

575

ret = gnutls_priority_set_direct(*session, mc.priority, &err);

779

576

if(quit_now){

780

577

gnutls_deinit(*session);

781

578

return -1;

792

589

793

590

do {

794

591

ret = gnutls_credentials_set(*session, GNUTLS_CRD_CERTIFICATE,

795

mc->cred);

592

mc.cred);

796

593

if(quit_now){

797

594

gnutls_deinit(*session);

798

595

return -1;

808

605

/* ignore client certificate if any. */

809

606

gnutls_certificate_server_set_request(*session, GNUTLS_CERT_IGNORE);

810

607

608

gnutls_dh_set_prime_bits(*session, mc.dh_bits);

609

811

610

return 0;

812

611

}

813

612

815

614

static void empty_log(__attribute__((unused)) AvahiLogLevel level,

816

615

__attribute__((unused)) const char *txt){}

817

616

818

/* Set effective uid to 0, return errno */

819

__attribute__((warn_unused_result))

820

int raise_privileges(void){

821

int old_errno = errno;

822

int ret = 0;

823

if(seteuid(0) == -1){

824

ret = errno;

825

}

826

errno = old_errno;

827

return ret;

828

}

829

830

/* Set effective and real user ID to 0. Return errno. */

831

__attribute__((warn_unused_result))

832

int raise_privileges_permanently(void){

833

int old_errno = errno;

834

int ret = raise_privileges();

835

if(ret != 0){

836

errno = old_errno;

837

return ret;

838

}

839

if(setuid(0) == -1){

840

ret = errno;

841

}

842

errno = old_errno;

843

return ret;

844

}

845

846

/* Set effective user ID to unprivileged saved user ID */

847

__attribute__((warn_unused_result))

848

int lower_privileges(void){

849

int old_errno = errno;

850

int ret = 0;

851

if(seteuid(uid) == -1){

852

ret = errno;

853

}

854

errno = old_errno;

855

return ret;

856

}

857

858

/* Lower privileges permanently */

859

__attribute__((warn_unused_result))

860

int lower_privileges_permanently(void){

861

int old_errno = errno;

862

int ret = 0;

863

if(setuid(uid) == -1){

864

ret = errno;

865

}

866

errno = old_errno;

867

return ret;

868

}

869

870

/* Helper function to add_local_route() and delete_local_route() */

871

__attribute__((nonnull, warn_unused_result))

872

static bool add_delete_local_route(const bool add,

873

const char *address,

874

AvahiIfIndex if_index){

875

int ret;

876

char helper[] = "mandos-client-iprouteadddel";

877

char add_arg[] = "add";

878

char delete_arg[] = "delete";

879

char debug_flag[] = "--debug";

880

char *pluginhelperdir = getenv("MANDOSPLUGINHELPERDIR");

881

if(pluginhelperdir == NULL){

882

if(debug){

883

fprintf_plus(stderr, "MANDOSPLUGINHELPERDIR environment"

884

" variable not set; cannot run helper\n");

885

}

886

return false;

887

}

888

889

char interface[IF_NAMESIZE];

890

if(if_indextoname((unsigned int)if_index, interface) == NULL){

891

perror_plus("if_indextoname");

892

return false;

893

}

894

895

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

896

if(devnull == -1){

897

perror_plus("open(\"/dev/null\", O_RDONLY)");

898

return false;

899

}

900

pid_t pid = fork();

901

if(pid == 0){

902

/* Child */

903

/* Raise privileges */

904

errno = raise_privileges_permanently();

905

if(errno != 0){

906

perror_plus("Failed to raise privileges");

907

/* _exit(EX_NOPERM); */

908

} else {

909

/* Set group */

910

errno = 0;

911

ret = setgid(0);

912

if(ret == -1){

913

perror_plus("setgid");

914

_exit(EX_NOPERM);

915

}

916

/* Reset supplementary groups */

917

errno = 0;

918

ret = setgroups(0, NULL);

919

if(ret == -1){

920

perror_plus("setgroups");

921

_exit(EX_NOPERM);

922

}

923

}

924

ret = dup2(devnull, STDIN_FILENO);

925

if(ret == -1){

926

perror_plus("dup2(devnull, STDIN_FILENO)");

927

_exit(EX_OSERR);

928

}

929

ret = close(devnull);

930

if(ret == -1){

931

perror_plus("close");

932

_exit(EX_OSERR);

933

}

934

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

935

if(ret == -1){

936

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

937

_exit(EX_OSERR);

938

}

939

int helperdir_fd = (int)TEMP_FAILURE_RETRY(open(pluginhelperdir,

940

O_RDONLY

941

| O_DIRECTORY

942

| O_PATH

943

| O_CLOEXEC));

944

if(helperdir_fd == -1){

945

perror_plus("open");

946

_exit(EX_UNAVAILABLE);

947

}

948

int helper_fd = (int)TEMP_FAILURE_RETRY(openat(helperdir_fd,

949

helper, O_RDONLY));

950

if(helper_fd == -1){

951

perror_plus("openat");

952

close(helperdir_fd);

953

_exit(EX_UNAVAILABLE);

954

}

955

close(helperdir_fd);

956

#ifdef __GNUC__

957

#pragma GCC diagnostic push

958

#pragma GCC diagnostic ignored "-Wcast-qual"

959

#endif

960

if(fexecve(helper_fd, (char *const [])

961

{ helper, add ? add_arg : delete_arg, (char *)address,

962

interface, debug ? debug_flag : NULL, NULL },

963

environ) == -1){

964

#ifdef __GNUC__

965

#pragma GCC diagnostic pop

966

#endif

967

perror_plus("fexecve");

968

_exit(EXIT_FAILURE);

969

}

970

}

971

if(pid == -1){

972

perror_plus("fork");

973

return false;

974

}

975

int status;

976

pid_t pret = -1;

977

errno = 0;

978

do {

979

pret = waitpid(pid, &status, 0);

980

if(pret == -1 and errno == EINTR and quit_now){

981

int errno_raising = 0;

982

if((errno = raise_privileges()) != 0){

983

errno_raising = errno;

984

perror_plus("Failed to raise privileges in order to"

985

" kill helper program");

986

}

987

if(kill(pid, SIGTERM) == -1){

988

perror_plus("kill");

989

}

990

if((errno_raising == 0) and (errno = lower_privileges()) != 0){

991

perror_plus("Failed to lower privileges after killing"

992

" helper program");

993

}

994

return false;

995

}

996

} while(pret == -1 and errno == EINTR);

997

if(pret == -1){

998

perror_plus("waitpid");

999

return false;

1000

}

1001

if(WIFEXITED(status)){

1002

if(WEXITSTATUS(status) != 0){

1003

fprintf_plus(stderr, "Error: iprouteadddel exited"

1004

" with status %d\n", WEXITSTATUS(status));

1005

return false;

1006

}

1007

return true;

1008

}

1009

if(WIFSIGNALED(status)){

1010

fprintf_plus(stderr, "Error: iprouteadddel died by"

1011

" signal %d\n", WTERMSIG(status));

1012

return false;

1013

}

1014

fprintf_plus(stderr, "Error: iprouteadddel crashed\n");

1015

return false;

1016

}

1017

1018

__attribute__((nonnull, warn_unused_result))

1019

static bool add_local_route(const char *address,

1020

AvahiIfIndex if_index){

1021

if(debug){

1022

fprintf_plus(stderr, "Adding route to %s\n", address);

1023

}

1024

return add_delete_local_route(true, address, if_index);

1025

}

1026

1027

__attribute__((nonnull, warn_unused_result))

1028

static bool delete_local_route(const char *address,

1029

AvahiIfIndex if_index){

1030

if(debug){

1031

fprintf_plus(stderr, "Removing route to %s\n", address);

1032

}

1033

return add_delete_local_route(false, address, if_index);

1034

}

1035

1036

617

/* Called when a Mandos server is found */

1037

__attribute__((nonnull, warn_unused_result))

1038

static int start_mandos_communication(const char *ip, in_port_t port,

618

static int start_mandos_communication(const char *ip, uint16_t port,

1039

619

AvahiIfIndex if_index,

1040

int af, mandos_context *mc){

620

int af){

1041

621

int ret, tcp_sd = -1;

1042

622

ssize_t sret;

1043

struct sockaddr_storage to;

623

union {

624

struct sockaddr_in in;

625

struct sockaddr_in6 in6;

626

} to;

1044

627

char *buffer = NULL;

1045

628

char *decrypted_buffer = NULL;

1046

629

size_t buffer_length = 0;

1049

632

int retval = -1;

1050

633

gnutls_session_t session;

1051

634

int pf; /* Protocol family */

1052

bool route_added = false;

1053

635

1054

636

errno = 0;

1055

637

1071

653

return -1;

1072

654

}

1073

655

1074

/* If the interface is specified and we have a list of interfaces */

1075

if(if_index != AVAHI_IF_UNSPEC and mc->interfaces != NULL){

1076

/* Check if the interface is one of the interfaces we are using */

1077

bool match = false;

1078

{

1079

char *interface = NULL;

1080

while((interface=argz_next(mc->interfaces, mc->interfaces_size,

1081

interface))){

1082

if(if_nametoindex(interface) == (unsigned int)if_index){

1083

match = true;

1084

break;

1085

}

1086

}

1087

}

1088

if(not match){

1089

/* This interface does not match any in the list, so we don't

1090

connect to the server */

1091

if(debug){

1092

char interface[IF_NAMESIZE];

1093

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1094

perror_plus("if_indextoname");

1095

} else {

1096

fprintf_plus(stderr, "Skipping server on non-used interface"

1097

" \"%s\"\n",

1098

if_indextoname((unsigned int)if_index,

1099

interface));

1100

}

1101

}

1102

return -1;

1103

}

1104

}

1105

1106

ret = init_gnutls_session(&session, mc);

656

ret = init_gnutls_session(&session);

1107

657

if(ret != 0){

1108

658

return -1;

1109

659

}

1110

660

1111

661

if(debug){

1112

662

fprintf_plus(stderr, "Setting up a TCP connection to %s, port %"

1113

PRIuMAX "\n", ip, (uintmax_t)port);

663

PRIu16 "\n", ip, port);

1114

664

}

1115

665

1116

tcp_sd = socket(pf, SOCK_STREAM | SOCK_CLOEXEC, 0);

666

tcp_sd = socket(pf, SOCK_STREAM, 0);

1117

667

if(tcp_sd < 0){

1118

668

int e = errno;

1119

669

perror_plus("socket");

1126

676

goto mandos_end;

1127

677

}

1128

678

679

memset(&to, 0, sizeof(to));

1129

680

if(af == AF_INET6){

1130

struct sockaddr_in6 *to6 = (struct sockaddr_in6 *)&to;

1131

*to6 = (struct sockaddr_in6){ .sin6_family = (sa_family_t)af };

1132

ret = inet_pton(af, ip, &to6->sin6_addr);

681

to.in6.sin6_family = (sa_family_t)af;

682

ret = inet_pton(af, ip, &to.in6.sin6_addr);

1133

683

} else { /* IPv4 */

1134

struct sockaddr_in *to4 = (struct sockaddr_in *)&to;

1135

*to4 = (struct sockaddr_in){ .sin_family = (sa_family_t)af };

1136

ret = inet_pton(af, ip, &to4->sin_addr);

684

to.in.sin_family = (sa_family_t)af;

685

ret = inet_pton(af, ip, &to.in.sin_addr);

1137

686

}

1138

687

if(ret < 0 ){

1139

688

int e = errno;

1148

697

goto mandos_end;

1149

698

}

1150

699

if(af == AF_INET6){

1151

((struct sockaddr_in6 *)&to)->sin6_port = htons(port);

1152

if(IN6_IS_ADDR_LINKLOCAL

1153

(&((struct sockaddr_in6 *)&to)->sin6_addr)){

700

to.in6.sin6_port = htons(port); /* Spurious warnings from

701

-Wconversion and

702

-Wunreachable-code */

703

704

if(IN6_IS_ADDR_LINKLOCAL /* Spurious warnings from */

705

(&to.in6.sin6_addr)){ /* -Wstrict-aliasing=2 or lower and

706

-Wunreachable-code*/

1154

707

if(if_index == AVAHI_IF_UNSPEC){

1155

708

fprintf_plus(stderr, "An IPv6 link-local address is"

1156

709

" incomplete without a network interface\n");

1158

711

goto mandos_end;

1159

712

}

1160

713

/* Set the network interface number as scope */

1161

((struct sockaddr_in6 *)&to)->sin6_scope_id = (uint32_t)if_index;

714

to.in6.sin6_scope_id = (uint32_t)if_index;

1162

715

}

1163

716

} else {

1164

((struct sockaddr_in *)&to)->sin_port = htons(port);

717

to.in.sin_port = htons(port); /* Spurious warnings from

718

-Wconversion and

719

-Wunreachable-code */

1165

720

}

1166

721

1167

722

if(quit_now){

1175

730

if(if_indextoname((unsigned int)if_index, interface) == NULL){

1176

731

perror_plus("if_indextoname");

1177

732

} else {

1178

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIuMAX

1179

"\n", ip, interface, (uintmax_t)port);

733

fprintf_plus(stderr, "Connection to: %s%%%s, port %" PRIu16

734

"\n", ip, interface, port);

1180

735

}

1181

736

} else {

1182

fprintf_plus(stderr, "Connection to: %s, port %" PRIuMAX "\n",

1183

ip, (uintmax_t)port);

737

fprintf_plus(stderr, "Connection to: %s, port %" PRIu16 "\n",

738

ip, port);

1184

739

}

1185

740

char addrstr[(INET_ADDRSTRLEN > INET6_ADDRSTRLEN) ?

1186

741

INET_ADDRSTRLEN : INET6_ADDRSTRLEN] = "";

1187

if(af == AF_INET6){

1188

ret = getnameinfo((struct sockaddr *)&to,

1189

sizeof(struct sockaddr_in6),

1190

addrstr, sizeof(addrstr), NULL, 0,

1191

NI_NUMERICHOST);

1192

} else {

1193

ret = getnameinfo((struct sockaddr *)&to,

1194

sizeof(struct sockaddr_in),

1195

addrstr, sizeof(addrstr), NULL, 0,

1196

NI_NUMERICHOST);

1197

}

1198

if(ret == EAI_SYSTEM){

1199

perror_plus("getnameinfo");

1200

} else if(ret != 0) {

1201

fprintf_plus(stderr, "getnameinfo: %s", gai_strerror(ret));

1202

} else if(strcmp(addrstr, ip) != 0){

1203

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

1204

}

1205

}

1206

1207

if(quit_now){

1208

errno = EINTR;

1209

goto mandos_end;

1210

}

1211

1212

while(true){

1213

if(af == AF_INET6){

1214

ret = connect(tcp_sd, (struct sockaddr *)&to,

1215

sizeof(struct sockaddr_in6));

1216

} else {

1217

ret = connect(tcp_sd, (struct sockaddr *)&to, /* IPv4 */

1218

sizeof(struct sockaddr_in));

1219

}

1220

if(ret < 0){

1221

if(((errno == ENETUNREACH) or (errno == EHOSTUNREACH))

1222

and if_index != AVAHI_IF_UNSPEC

1223

and connect_to == NULL

1224

and not route_added and

1225

((af == AF_INET6 and not

1226

IN6_IS_ADDR_LINKLOCAL(&(((struct sockaddr_in6 *)

1227

&to)->sin6_addr)))

1228

or (af == AF_INET and

1229

/* Not a a IPv4LL address */

1230

(ntohl(((struct sockaddr_in *)&to)->sin_addr.s_addr)

1231

& 0xFFFF0000L) != 0xA9FE0000L))){

1232

/* Work around Avahi bug - Avahi does not announce link-local

1233

addresses if it has a global address, so local hosts with

1234

*only* a link-local address (e.g. Mandos clients) cannot

1235

connect to a Mandos server announced by Avahi on a server

1236

host with a global address. Work around this by retrying

1237

with an explicit route added with the server's address.

1238

1239

Avahi bug reference:

1240

http://lists.freedesktop.org/archives/avahi/2010-February/001833.html

1241

https://bugs.debian.org/587961

1242

*/

1243

if(debug){

1244

fprintf_plus(stderr, "Mandos server unreachable, trying"

1245

" direct route\n");

1246

}

1247

int e = errno;

1248

route_added = add_local_route(ip, if_index);

1249

if(route_added){

1250

continue;

1251

}

1252

errno = e;

1253

}

1254

if(errno != ECONNREFUSED or debug){

1255

int e = errno;

1256

perror_plus("connect");

1257

errno = e;

1258

}

1259

goto mandos_end;

1260

}

1261

1262

if(quit_now){

1263

errno = EINTR;

1264

goto mandos_end;

1265

}

1266

break;

742

const char *pcret;

743

if(af == AF_INET6){

744

pcret = inet_ntop(af, &(to.in6.sin6_addr), addrstr,

745

sizeof(addrstr));

746

} else {

747

pcret = inet_ntop(af, &(to.in.sin_addr), addrstr,

748

sizeof(addrstr));

749

}

750

if(pcret == NULL){

751

perror_plus("inet_ntop");

752

} else {

753

if(strcmp(addrstr, ip) != 0){

754

fprintf_plus(stderr, "Canonical address form: %s\n", addrstr);

755

}

756

}

757

}

758

759

if(quit_now){

760

errno = EINTR;

761

goto mandos_end;

762

}

763

764

if(af == AF_INET6){

765

ret = connect(tcp_sd, &to.in6, sizeof(to));

766

} else {

767

ret = connect(tcp_sd, &to.in, sizeof(to)); /* IPv4 */

768

}

769

if(ret < 0){

770

if ((errno != ECONNREFUSED and errno != ENETUNREACH) or debug){

771

int e = errno;

772

perror_plus("connect");

773

errno = e;

774

}

775

goto mandos_end;

776

}

777

778

if(quit_now){

779

errno = EINTR;

780

goto mandos_end;

1267

781

}

1268

782

1269

783

const char *out = mandos_protocol_version;

1305

819

goto mandos_end;

1306

820

}

1307

821

1308

/* This casting via intptr_t is to eliminate warning about casting

1309

an int to a pointer type. This is exactly how the GnuTLS Guile

1310

function "set-session-transport-fd!" does it. */

1311

gnutls_transport_set_ptr(session,

1312

(gnutls_transport_ptr_t)(intptr_t)tcp_sd);

822

/* Spurious warning from -Wint-to-pointer-cast */

823

gnutls_transport_set_ptr(session, (gnutls_transport_ptr_t) tcp_sd);

1313

824

1314

825

if(quit_now){

1315

826

errno = EINTR;

1420

931

if(buffer_length > 0){

1421

932

ssize_t decrypted_buffer_size;

1422

933

decrypted_buffer_size = pgp_packet_decrypt(buffer, buffer_length,

1423

&decrypted_buffer, mc);

934

&decrypted_buffer);

1424

935

if(decrypted_buffer_size >= 0){

1425

936

1426

clearerr(stdout);

1427

937

written = 0;

1428

938

while(written < (size_t) decrypted_buffer_size){

1429

939

if(quit_now){

1445

955

}

1446

956

written += (size_t)ret;

1447

957

}

1448

ret = fflush(stdout);

1449

if(ret != 0){

1450

int e = errno;

1451

if(debug){

1452

fprintf_plus(stderr, "Error writing encrypted data: %s\n",

1453

strerror(errno));

1454

}

1455

errno = e;

1456

goto mandos_end;

1457

}

1458

958

retval = 0;

1459

959

}

1460

960

}

1463

963

1464

964

mandos_end:

1465

965

{

1466

if(route_added){

1467

if(not delete_local_route(ip, if_index)){

1468

fprintf_plus(stderr, "Failed to delete local route to %s on"

1469

" interface %d", ip, if_index);

1470

}

1471

}

1472

966

int e = errno;

1473

967

free(decrypted_buffer);

1474

968

free(buffer);

1475

969

if(tcp_sd >= 0){

1476

ret = close(tcp_sd);

970

ret = (int)TEMP_FAILURE_RETRY(close(tcp_sd));

1477

971

}

1478

972

if(ret == -1){

1479

973

if(e == 0){

1491

985

return retval;

1492

986

}

1493

987

1494

__attribute__((nonnull))

1495

988

static void resolve_callback(AvahiSServiceResolver *r,

1496

989

AvahiIfIndex interface,

1497

990

AvahiProtocol proto,

1505

998

AVAHI_GCC_UNUSED AvahiStringList *txt,

1506

999

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1507

1000

flags,

1508

void *mc){

1509

if(r == NULL){

1510

return;

1511

}

1001

AVAHI_GCC_UNUSED void* userdata){

1002

assert(r);

1512

1003

1513

1004

/* Called whenever a service has been resolved successfully or

1514

1005

timed out */

1515

1006

1516

1007

if(quit_now){

1517

avahi_s_service_resolver_free(r);

1518

1008

return;

1519

1009

}

1520

1010

1524

1014

fprintf_plus(stderr, "(Avahi Resolver) Failed to resolve service "

1525

1015

"'%s' of type '%s' in domain '%s': %s\n", name, type,

1526

1016

domain,

1527

avahi_strerror(avahi_server_errno

1528

(((mandos_context*)mc)->server)));

1017

avahi_strerror(avahi_server_errno(mc.server)));

1529

1018

break;

1530

1019

1531

1020

case AVAHI_RESOLVER_FOUND:

1537

1026

PRIdMAX ") on port %" PRIu16 "\n", name,

1538

1027

host_name, ip, (intmax_t)interface, port);

1539

1028

}

1540

int ret = start_mandos_communication(ip, (in_port_t)port,

1541

interface,

1542

avahi_proto_to_af(proto),

1543

mc);

1029

int ret = start_mandos_communication(ip, port, interface,

1030

avahi_proto_to_af(proto));

1544

1031

if(ret == 0){

1545

avahi_simple_poll_quit(simple_poll);

1032

avahi_simple_poll_quit(mc.simple_poll);

1546

1033

} else {

1547

if(not add_server(ip, (in_port_t)port, interface,

1548

avahi_proto_to_af(proto),

1549

&((mandos_context*)mc)->current_server)){

1034

if(not add_server(ip, port, interface,

1035

avahi_proto_to_af(proto))){

1550

1036

fprintf_plus(stderr, "Failed to add server \"%s\" to server"

1551

1037

" list\n", name);

1552

1038

}

1565

1051

const char *domain,

1566

1052

AVAHI_GCC_UNUSED AvahiLookupResultFlags

1567

1053

flags,

1568

void *mc){

1569

if(b == NULL){

1570

return;

1571

}

1054

AVAHI_GCC_UNUSED void* userdata){

1055

assert(b);

1572

1056

1573

1057

/* Called whenever a new services becomes available on the LAN or

1574

1058

is removed from the LAN */

1582

1066

case AVAHI_BROWSER_FAILURE:

1583

1067

1584

1068

fprintf_plus(stderr, "(Avahi browser) %s\n",

1585

avahi_strerror(avahi_server_errno

1586

(((mandos_context*)mc)->server)));

1587

avahi_simple_poll_quit(simple_poll);

1069

avahi_strerror(avahi_server_errno(mc.server)));

1070

avahi_simple_poll_quit(mc.simple_poll);

1588

1071

return;

1589

1072

1590

1073

case AVAHI_BROWSER_NEW:

1593

1076

the callback function is called the Avahi server will free the

1594

1077

resolver for us. */

1595

1078

1596

if(avahi_s_service_resolver_new(((mandos_context*)mc)->server,

1597

interface, protocol, name, type,

1598

domain, protocol, 0,

1599

resolve_callback, mc) == NULL)

1079

if(avahi_s_service_resolver_new(mc.server, interface, protocol,

1080

name, type, domain, protocol, 0,

1081

resolve_callback, NULL) == NULL)

1600

1082

fprintf_plus(stderr, "Avahi: Failed to resolve service '%s':"

1601

1083

" %s\n", name,

1602

avahi_strerror(avahi_server_errno

1603

(((mandos_context*)mc)->server)));

1084

avahi_strerror(avahi_server_errno(mc.server)));

1604

1085

break;

1605

1086

1606

1087

case AVAHI_BROWSER_REMOVE:

1625

1106

signal_received = sig;

1626

1107

int old_errno = errno;

1627

1108

/* set main loop to exit */

1628

if(simple_poll != NULL){

1629

avahi_simple_poll_quit(simple_poll);

1109

if(mc.simple_poll != NULL){

1110

avahi_simple_poll_quit(mc.simple_poll);

1630

1111

}

1631

1112

errno = old_errno;

1632

1113

}

1633

1114

1634

__attribute__((nonnull, warn_unused_result))

1635

1115

bool get_flags(const char *ifname, struct ifreq *ifr){

1636

1116

int ret;

1637

int old_errno;

1638

1117

1639

1118

int s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1640

1119

if(s < 0){

1641

old_errno = errno;

1642

1120

perror_plus("socket");

1643

errno = old_errno;

1644

1121

return false;

1645

1122

}

1646

strncpy(ifr->ifr_name, ifname, IF_NAMESIZE);

1647

ifr->ifr_name[IF_NAMESIZE-1] = '\0'; /* NUL terminate */

1123

strcpy(ifr->ifr_name, ifname);

1648

1124

ret = ioctl(s, SIOCGIFFLAGS, ifr);

1649

1125

if(ret == -1){

1650

1126

if(debug){

1651

old_errno = errno;

1652

1127

perror_plus("ioctl SIOCGIFFLAGS");

1653

errno = old_errno;

1654

1128

}

1655

1129

return false;

1656

1130

}

1657

1131

return true;

1658

1132

}

1659

1133

1660

__attribute__((nonnull, warn_unused_result))

1661

1134

bool good_flags(const char *ifname, const struct ifreq *ifr){

1662

1135

1663

1136

/* Reject the loopback device */

1705

1178

* corresponds to an acceptable network device.

1706

1179

* (This function is passed to scandir(3) as a filter function.)

1707

1180

*/

1708

__attribute__((nonnull, warn_unused_result))

1709

1181

int good_interface(const struct dirent *if_entry){

1710

1182

if(if_entry->d_name[0] == '.'){

1711

1183

return 0;

1727

1199

}

1728

1200

1729

1201

/*

1730

* This function determines if a network interface is up.

1731

*/

1732

__attribute__((nonnull, warn_unused_result))

1733

bool interface_is_up(const char *interface){

1734

struct ifreq ifr;

1735

if(not get_flags(interface, &ifr)){

1736

if(debug){

1737

fprintf_plus(stderr, "Failed to get flags for interface "

1738

"\"%s\"\n", interface);

1739

}

1740

return false;

1741

}

1742

1743

return (bool)(ifr.ifr_flags & IFF_UP);

1744

}

1745

1746

/*

1747

* This function determines if a network interface is running

1748

*/

1749

__attribute__((nonnull, warn_unused_result))

1750

bool interface_is_running(const char *interface){

1751

struct ifreq ifr;

1752

if(not get_flags(interface, &ifr)){

1753

if(debug){

1754

fprintf_plus(stderr, "Failed to get flags for interface "

1755

"\"%s\"\n", interface);

1756

}

1757

return false;

1758

}

1759

1760

return (bool)(ifr.ifr_flags & IFF_RUNNING);

1761

}

1762

1763

__attribute__((nonnull, pure, warn_unused_result))

1202

* This function determines if a directory entry in /sys/class/net

1203

* corresponds to an acceptable network device which is up.

1204

* (This function is passed to scandir(3) as a filter function.)

1205

*/

1206

int up_interface(const struct dirent *if_entry){

1207

if(if_entry->d_name[0] == '.'){

1208

return 0;

1209

}

1210

1211

struct ifreq ifr;

1212

if(not get_flags(if_entry->d_name, &ifr)){

1213

if(debug){

1214

fprintf_plus(stderr, "Failed to get flags for interface "

1215

"\"%s\"\n", if_entry->d_name);

1216

}

1217

return 0;

1218

}

1219

1220

/* Reject down interfaces */

1221

if(not (ifr.ifr_flags & IFF_UP)){

1222

if(debug){

1223

fprintf_plus(stderr, "Rejecting down interface \"%s\"\n",

1224

if_entry->d_name);

1225

}

1226

return 0;

1227

}

1228

1229

/* Reject non-running interfaces */

1230

if(not (ifr.ifr_flags & IFF_RUNNING)){

1231

if(debug){

1232

fprintf_plus(stderr, "Rejecting non-running interface \"%s\"\n",

1233

if_entry->d_name);

1234

}

1235

return 0;

1236

}

1237

1238

if(not good_flags(if_entry->d_name, &ifr)){

1239

return 0;

1240

}

1241

return 1;

1242

}

1243

1764

1244

int notdotentries(const struct dirent *direntry){

1765

1245

/* Skip "." and ".." */

1766

1246

if(direntry->d_name[0] == '.'

1773

1253

}

1774

1254

1775

1255

/* Is this directory entry a runnable program? */

1776

__attribute__((nonnull, warn_unused_result))

1777

1256

int runnable_hook(const struct dirent *direntry){

1778

1257

int ret;

1779

1258

size_t sret;

1787

1266

sret = strspn(direntry->d_name, "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

1788

1267

"abcdefghijklmnopqrstuvwxyz"

1789

1268

"0123456789"

1790

"_.-");

1269

"_-");

1791

1270

if((direntry->d_name)[sret] != '\0'){

1792

1271

/* Contains non-allowed characters */

1793

1272

if(debug){

1797

1276

return 0;

1798

1277

}

1799

1278

1800

ret = fstatat(hookdir_fd, direntry->d_name, &st, 0);

1279

char *fullname = NULL;

1280

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1281

if(ret < 0){

1282

perror_plus("asprintf");

1283

return 0;

1284

}

1285

1286

ret = stat(fullname, &st);

1801

1287

if(ret == -1){

1802

1288

if(debug){

1803

1289

perror_plus("Could not stat hook");

1827

1313

return 1;

1828

1314

}

1829

1315

1830

__attribute__((nonnull, warn_unused_result))

1831

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval,

1832

mandos_context *mc){

1316

int avahi_loop_with_timeout(AvahiSimplePoll *s, int retry_interval){

1833

1317

int ret;

1834

1318

struct timespec now;

1835

1319

struct timespec waited_time;

1836

1320

intmax_t block_time;

1837

1321

1838

1322

while(true){

1839

if(mc->current_server == NULL){

1840

if(debug){

1323

if(mc.current_server == NULL){

1324

if (debug){

1841

1325

fprintf_plus(stderr, "Wait until first server is found."

1842

1326

" No timeout!\n");

1843

1327

}

1844

1328

ret = avahi_simple_poll_iterate(s, -1);

1845

1329

} else {

1846

if(debug){

1330

if (debug){

1847

1331

fprintf_plus(stderr, "Check current_server if we should run"

1848

1332

" it, or wait\n");

1849

1333

}

1856

1340

/* Calculating in ms how long time between now and server

1857

1341

who we visted longest time ago. Now - last seen. */

1858

1342

waited_time.tv_sec = (now.tv_sec

1859

- mc->current_server->last_seen.tv_sec);

1343

- mc.current_server->last_seen.tv_sec);

1860

1344

waited_time.tv_nsec = (now.tv_nsec

1861

- mc->current_server->last_seen.tv_nsec);

1345

- mc.current_server->last_seen.tv_nsec);

1862

1346

/* total time is 10s/10,000ms.

1863

1347

Converting to s from ms by dividing by 1,000,

1864

1348

and ns to ms by dividing by 1,000,000. */

1866

1350

- ((intmax_t)waited_time.tv_sec * 1000))

1867

1351

- ((intmax_t)waited_time.tv_nsec / 1000000));

1868

1352

1869

if(debug){

1353

if (debug){

1870

1354

fprintf_plus(stderr, "Blocking for %" PRIdMAX " ms\n",

1871

1355

block_time);

1872

1356

}

1873

1357

1874

1358

if(block_time <= 0){

1875

ret = start_mandos_communication(mc->current_server->ip,

1876

mc->current_server->port,

1877

mc->current_server->if_index,

1878

mc->current_server->af, mc);

1359

ret = start_mandos_communication(mc.current_server->ip,

1360

mc.current_server->port,

1361

mc.current_server->if_index,

1362

mc.current_server->af);

1879

1363

if(ret == 0){

1880

avahi_simple_poll_quit(s);

1364

avahi_simple_poll_quit(mc.simple_poll);

1881

1365

return 0;

1882

1366

}

1883

1367

ret = clock_gettime(CLOCK_MONOTONIC,

1884

&mc->current_server->last_seen);

1368

&mc.current_server->last_seen);

1885

1369

if(ret == -1){

1886

1370

perror_plus("clock_gettime");

1887

1371

return -1;

1888

1372

}

1889

mc->current_server = mc->current_server->next;

1373

mc.current_server = mc.current_server->next;

1890

1374

block_time = 0; /* Call avahi to find new Mandos

1891

1375

servers, but don't block */

1892

1376

}

1894

1378

ret = avahi_simple_poll_iterate(s, (int)block_time);

1895

1379

}

1896

1380

if(ret != 0){

1897

if(ret > 0 or errno != EINTR){

1381

if (ret > 0 or errno != EINTR){

1898

1382

return (ret != 1) ? ret : 0;

1899

1383

}

1900

1384

}

1901

1385

}

1902

1386

}

1903

1387

1904

__attribute__((nonnull))

1905

void run_network_hooks(const char *mode, const char *interface,

1388

bool run_network_hooks(const char *mode, const char *interface,

1906

1389

const float delay){

1907

struct dirent **direntries = NULL;

1908

if(hookdir_fd == -1){

1909

hookdir_fd = open(hookdir, O_RDONLY | O_DIRECTORY | O_PATH

1910

| O_CLOEXEC);

1911

if(hookdir_fd == -1){

1912

if(errno == ENOENT){

1913

if(debug){

1914

fprintf_plus(stderr, "Network hook directory \"%s\" not"

1915

" found\n", hookdir);

1916

}

1917

} else {

1918

perror_plus("open");

1919

}

1920

return;

1921

}

1922

}

1923

int numhooks = scandirat(hookdir_fd, ".", &direntries,

1924

runnable_hook, alphasort);

1390

struct dirent **direntries;

1391

struct dirent *direntry;

1392

int ret;

1393

int numhooks = scandir(hookdir, &direntries, runnable_hook,

1394

alphasort);

1925

1395

if(numhooks == -1){

1926

1396

perror_plus("scandir");

1927

return;

1928

}

1929

struct dirent *direntry;

1930

int ret;

1931

int devnull = (int)TEMP_FAILURE_RETRY(open("/dev/null", O_RDONLY));

1932

if(devnull == -1){

1933

perror_plus("open(\"/dev/null\", O_RDONLY)");

1934

return;

1935

}

1936

for(int i = 0; i < numhooks; i++){

1937

direntry = direntries[i];

1938

if(debug){

1939

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1940

direntry->d_name);

1941

}

1942

pid_t hook_pid = fork();

1943

if(hook_pid == 0){

1944

/* Child */

1945

/* Raise privileges */

1946

errno = raise_privileges_permanently();

1947

if(errno != 0){

1948

perror_plus("Failed to raise privileges");

1949

_exit(EX_NOPERM);

1950

}

1951

/* Set group */

1952

errno = 0;

1953

ret = setgid(0);

1954

if(ret == -1){

1955

perror_plus("setgid");

1956

_exit(EX_NOPERM);

1957

}

1958

/* Reset supplementary groups */

1959

errno = 0;

1960

ret = setgroups(0, NULL);

1961

if(ret == -1){

1962

perror_plus("setgroups");

1963

_exit(EX_NOPERM);

1964

}

1965

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1966

if(ret == -1){

1967

perror_plus("setenv");

1968

_exit(EX_OSERR);

1969

}

1970

ret = setenv("DEVICE", interface, 1);

1971

if(ret == -1){

1972

perror_plus("setenv");

1973

_exit(EX_OSERR);

1974

}

1975

ret = setenv("VERBOSITY", debug ? "1" : "0", 1);

1976

if(ret == -1){

1977

perror_plus("setenv");

1978

_exit(EX_OSERR);

1979

}

1980

ret = setenv("MODE", mode, 1);

1981

if(ret == -1){

1982

perror_plus("setenv");

1983

_exit(EX_OSERR);

1984

}

1985

char *delaystring;

1986

ret = asprintf(&delaystring, "%f", (double)delay);

1987

if(ret == -1){

1397

} else {

1398

int devnull = open("/dev/null", O_RDONLY);

1399

for(int i = 0; i < numhooks; i++){

1400

direntry = direntries[i];

1401

char *fullname = NULL;

1402

ret = asprintf(&fullname, "%s/%s", hookdir, direntry->d_name);

1403

if(ret < 0){

1988

1404

perror_plus("asprintf");

1989

_exit(EX_OSERR);

1990

}

1991

ret = setenv("DELAY", delaystring, 1);

1992

if(ret == -1){

1405

continue;

1406

}

1407

if(debug){

1408

fprintf_plus(stderr, "Running network hook \"%s\"\n",

1409

direntry->d_name);

1410

}

1411

pid_t hook_pid = fork();

1412

if(hook_pid == 0){

1413

/* Child */

1414

/* Raise privileges */

1415

errno = 0;

1416

ret = seteuid(0);

1417

if(ret == -1){

1418

perror_plus("seteuid");

1419

}

1420

/* Raise privileges even more */

1421

errno = 0;

1422

ret = setuid(0);

1423

if(ret == -1){

1424

perror_plus("setuid");

1425

}

1426

/* Set group */

1427

errno = 0;

1428

ret = setgid(0);

1429

if(ret == -1){

1430

perror_plus("setgid");

1431

}

1432

/* Reset supplementary groups */

1433

errno = 0;

1434

ret = setgroups(0, NULL);

1435

if(ret == -1){

1436

perror_plus("setgroups");

1437

}

1438

dup2(devnull, STDIN_FILENO);

1439

close(devnull);

1440

dup2(STDERR_FILENO, STDOUT_FILENO);

1441

ret = setenv("MANDOSNETHOOKDIR", hookdir, 1);

1442

if(ret == -1){

1443

perror_plus("setenv");

1444

_exit(EX_OSERR);

1445

}

1446

ret = setenv("DEVICE", interface, 1);

1447

if(ret == -1){

1448

perror_plus("setenv");

1449

_exit(EX_OSERR);

1450

}

1451

ret = setenv("VERBOSE", debug ? "1" : "0", 1);

1452

if(ret == -1){

1453

perror_plus("setenv");

1454

_exit(EX_OSERR);

1455

}

1456

ret = setenv("MODE", mode, 1);

1457

if(ret == -1){

1458

perror_plus("setenv");

1459

_exit(EX_OSERR);

1460

}

1461

char *delaystring;

1462

ret = asprintf(&delaystring, "%f", delay);

1463

if(ret == -1){

1464

perror_plus("asprintf");

1465

_exit(EX_OSERR);

1466

}

1467

ret = setenv("DELAY", delaystring, 1);

1468

if(ret == -1){

1469

free(delaystring);

1470

perror_plus("setenv");

1471

_exit(EX_OSERR);

1472

}

1993

1473

free(delaystring);

1994

perror_plus("setenv");

1995

_exit(EX_OSERR);

1996

}

1997

free(delaystring);

1998

if(connect_to != NULL){

1999

ret = setenv("CONNECT", connect_to, 1);

2000

if(ret == -1){

2001

perror_plus("setenv");

2002

_exit(EX_OSERR);

2003

}

2004

}

2005

int hook_fd = (int)TEMP_FAILURE_RETRY(openat(hookdir_fd,

2006

direntry->d_name,

2007

O_RDONLY));

2008

if(hook_fd == -1){

2009

perror_plus("openat");

2010

_exit(EXIT_FAILURE);

2011

}

2012

if(close(hookdir_fd) == -1){

2013

perror_plus("close");

2014

_exit(EXIT_FAILURE);

2015

}

2016

ret = dup2(devnull, STDIN_FILENO);

2017

if(ret == -1){

2018

perror_plus("dup2(devnull, STDIN_FILENO)");

2019

_exit(EX_OSERR);

2020

}

2021

ret = close(devnull);

2022

if(ret == -1){

2023

perror_plus("close");

2024

_exit(EX_OSERR);

2025

}

2026

ret = dup2(STDERR_FILENO, STDOUT_FILENO);

2027

if(ret == -1){

2028

perror_plus("dup2(STDERR_FILENO, STDOUT_FILENO)");

2029

_exit(EX_OSERR);

2030

}

2031

if(fexecve(hook_fd, (char *const []){ direntry->d_name, NULL },

2032

environ) == -1){

2033

perror_plus("fexecve");

2034

_exit(EXIT_FAILURE);

2035

}

2036

} else {

2037

if(hook_pid == -1){

2038

perror_plus("fork");

2039

free(direntry);

2040

continue;

2041

}

2042

int status;

2043

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

2044

perror_plus("waitpid");

2045

free(direntry);

2046

continue;

2047

}

2048

if(WIFEXITED(status)){

2049

if(WEXITSTATUS(status) != 0){

2050

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

2051

" with status %d\n", direntry->d_name,

2052

WEXITSTATUS(status));

2053

free(direntry);

2054

continue;

2055

}

2056

} else if(WIFSIGNALED(status)){

2057

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

2058

" signal %d\n", direntry->d_name,

2059

WTERMSIG(status));

2060

free(direntry);

2061

continue;

2062

} else {

2063

fprintf_plus(stderr, "Warning: network hook \"%s\""

2064

" crashed\n", direntry->d_name);

2065

free(direntry);

2066

continue;

2067

}

2068

}

2069

if(debug){

2070

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

2071

direntry->d_name);

2072

}

2073

free(direntry);

2074

}

2075

free(direntries);

2076

if(close(hookdir_fd) == -1){

2077

perror_plus("close");

2078

} else {

2079

hookdir_fd = -1;

2080

}

2081

close(devnull);

2082

}

2083

2084

__attribute__((nonnull, warn_unused_result))

2085

int bring_up_interface(const char *const interface,

2086

const float delay){

2087

int old_errno = errno;

2088

int ret;

2089

struct ifreq network;

2090

unsigned int if_index = if_nametoindex(interface);

2091

if(if_index == 0){

2092

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2093

errno = old_errno;

2094

return ENXIO;

2095

}

2096

2097

if(quit_now){

2098

errno = old_errno;

2099

return EINTR;

2100

}

2101

2102

if(not interface_is_up(interface)){

2103

int ret_errno = 0;

2104

int ioctl_errno = 0;

2105

if(not get_flags(interface, &network)){

2106

ret_errno = errno;

2107

fprintf_plus(stderr, "Failed to get flags for interface "

2108

"\"%s\"\n", interface);

2109

errno = old_errno;

2110

return ret_errno;

2111

}

2112

network.ifr_flags |= IFF_UP; /* set flag */

2113

2114

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2115

if(sd == -1){

2116

ret_errno = errno;

2117

perror_plus("socket");

2118

errno = old_errno;

2119

return ret_errno;

2120

}

2121

2122

if(quit_now){

2123

ret = close(sd);

2124

if(ret == -1){

2125

perror_plus("close");

2126

}

2127

errno = old_errno;

2128

return EINTR;

2129

}

2130

2131

if(debug){

2132

fprintf_plus(stderr, "Bringing up interface \"%s\"\n",

2133

interface);

2134

}

2135

2136

/* Raise privileges */

2137

ret_errno = raise_privileges();

2138

if(ret_errno != 0){

2139

errno = ret_errno;

2140

perror_plus("Failed to raise privileges");

2141

}

2142

2143

#ifdef __linux__

2144

int ret_linux;

2145

bool restore_loglevel = false;

2146

if(ret_errno == 0){

2147

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

2148

messages about the network interface to mess up the prompt */

2149

ret_linux = klogctl(8, NULL, 5);

2150

if(ret_linux == -1){

2151

perror_plus("klogctl");

2152

} else {

2153

restore_loglevel = true;

2154

}

2155

}

2156

#endif /* __linux__ */

2157

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2158

ioctl_errno = errno;

2159

#ifdef __linux__

2160

if(restore_loglevel){

2161

ret_linux = klogctl(7, NULL, 0);

2162

if(ret_linux == -1){

2163

perror_plus("klogctl");

2164

}

2165

}

2166

#endif /* __linux__ */

2167

2168

/* If raise_privileges() succeeded above */

2169

if(ret_errno == 0){

2170

/* Lower privileges */

2171

ret_errno = lower_privileges();

2172

if(ret_errno != 0){

2173

errno = ret_errno;

2174

perror_plus("Failed to lower privileges");

2175

}

2176

}

2177

2178

/* Close the socket */

2179

ret = close(sd);

2180

if(ret == -1){

2181

perror_plus("close");

2182

}

2183

2184

if(ret_setflags == -1){

2185

errno = ioctl_errno;

2186

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

2187

errno = old_errno;

2188

return ioctl_errno;

2189

}

2190

} else if(debug){

2191

fprintf_plus(stderr, "Interface \"%s\" is already up; good\n",

2192

interface);

2193

}

2194

2195

/* Sleep checking until interface is running.

2196

Check every 0.25s, up to total time of delay */

2197

for(int i=0; i < delay * 4; i++){

2198

if(interface_is_running(interface)){

2199

break;

2200

}

2201

struct timespec sleeptime = { .tv_nsec = 250000000 };

2202

ret = nanosleep(&sleeptime, NULL);

2203

if(ret == -1 and errno != EINTR){

2204

perror_plus("nanosleep");

2205

}

2206

}

2207

2208

errno = old_errno;

2209

return 0;

2210

}

2211

2212

__attribute__((nonnull, warn_unused_result))

2213

int take_down_interface(const char *const interface){

2214

int old_errno = errno;

2215

struct ifreq network;

2216

unsigned int if_index = if_nametoindex(interface);

2217

if(if_index == 0){

2218

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

2219

errno = old_errno;

2220

return ENXIO;

2221

}

2222

if(interface_is_up(interface)){

2223

int ret_errno = 0;

2224

int ioctl_errno = 0;

2225

if(not get_flags(interface, &network) and debug){

2226

ret_errno = errno;

2227

fprintf_plus(stderr, "Failed to get flags for interface "

2228

"\"%s\"\n", interface);

2229

errno = old_errno;

2230

return ret_errno;

2231

}

2232

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2233

2234

int sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

2235

if(sd == -1){

2236

ret_errno = errno;

2237

perror_plus("socket");

2238

errno = old_errno;

2239

return ret_errno;

2240

}

2241

2242

if(debug){

2243

fprintf_plus(stderr, "Taking down interface \"%s\"\n",

2244

interface);

2245

}

2246

2247

/* Raise privileges */

2248

ret_errno = raise_privileges();

2249

if(ret_errno != 0){

2250

errno = ret_errno;

2251

perror_plus("Failed to raise privileges");

2252

}

2253

2254

int ret_setflags = ioctl(sd, SIOCSIFFLAGS, &network);

2255

ioctl_errno = errno;

2256

2257

/* If raise_privileges() succeeded above */

2258

if(ret_errno == 0){

2259

/* Lower privileges */

2260

ret_errno = lower_privileges();

2261

if(ret_errno != 0){

2262

errno = ret_errno;

2263

perror_plus("Failed to lower privileges");

2264

}

2265

}

2266

2267

/* Close the socket */

2268

int ret = close(sd);

2269

if(ret == -1){

2270

perror_plus("close");

2271

}

2272

2273

if(ret_setflags == -1){

2274

errno = ioctl_errno;

2275

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2276

errno = old_errno;

2277

return ioctl_errno;

2278

}

2279

} else if(debug){

2280

fprintf_plus(stderr, "Interface \"%s\" is already down; odd\n",

2281

interface);

2282

}

2283

2284

errno = old_errno;

2285

return 0;

1474

if(execl(fullname, direntry->d_name, mode, NULL) == -1){

1475

perror_plus("execl");

1476

_exit(EXIT_FAILURE);

1477

}

1478

} else {

1479

int status;

1480

if(TEMP_FAILURE_RETRY(waitpid(hook_pid, &status, 0)) == -1){

1481

perror_plus("waitpid");

1482

free(fullname);

1483

continue;

1484

}

1485

if(WIFEXITED(status)){

1486

if(WEXITSTATUS(status) != 0){

1487

fprintf_plus(stderr, "Warning: network hook \"%s\" exited"

1488

" with status %d\n", direntry->d_name,

1489

WEXITSTATUS(status));

1490

free(fullname);

1491

continue;

1492

}

1493

} else if(WIFSIGNALED(status)){

1494

fprintf_plus(stderr, "Warning: network hook \"%s\" died by"

1495

" signal %d\n", direntry->d_name,

1496

WTERMSIG(status));

1497

free(fullname);

1498

continue;

1499

} else {

1500

fprintf_plus(stderr, "Warning: network hook \"%s\""

1501

" crashed\n", direntry->d_name);

1502

free(fullname);

1503

continue;

1504

}

1505

}

1506

free(fullname);

1507

if(debug){

1508

fprintf_plus(stderr, "Network hook \"%s\" ran successfully\n",

1509

direntry->d_name);

1510

}

1511

}

1512

close(devnull);

1513

}

1514

return true;

2286

1515

}

2287

1516

2288

1517

int main(int argc, char *argv[]){

2289

mandos_context mc = { .server = NULL, .dh_bits = 0,

2290

.priority = "SECURE256:!CTYPE-X.509"

2291

":+CTYPE-OPENPGP:!RSA:+SIGN-DSA-SHA256",

2292

.current_server = NULL, .interfaces = NULL,

2293

.interfaces_size = 0 };

2294

1518

AvahiSServiceBrowser *sb = NULL;

2295

error_t ret_errno;

1519

int error;

2296

1520

int ret;

2297

1521

intmax_t tmpmax;

2298

1522

char *tmp;

2299

1523

int exitcode = EXIT_SUCCESS;

2300

char *interfaces_to_take_down = NULL;

2301

size_t interfaces_to_take_down_size = 0;

2302

char run_tempdir[] = "/run/tmp/mandosXXXXXX";

2303

char old_tempdir[] = "/tmp/mandosXXXXXX";

2304

char *tempdir = NULL;

1524

const char *interface = "";

1525

struct ifreq network;

1526

int sd = -1;

1527

bool take_down_interface = false;

1528

uid_t uid;

1529

gid_t gid;

1530

char tempdir[] = "/tmp/mandosXXXXXX";

1531

bool tempdir_created = false;

2305

1532

AvahiIfIndex if_index = AVAHI_IF_UNSPEC;

2306

1533

const char *seckey = PATHDIR "/" SECKEY;

2307

1534

const char *pubkey = PATHDIR "/" PUBKEY;

2308

const char *dh_params_file = NULL;

2309

char *interfaces_hooks = NULL;

2310

1535

2311

1536

bool gnutls_initialized = false;

2312

1537

bool gpgme_initialized = false;

2364

1589

.doc = "Bit length of the prime number used in the"

2365

1590

" Diffie-Hellman key exchange",

2366

1591

.group = 2 },

2367

{ .name = "dh-params", .key = 134,

2368

.arg = "FILE",

2369

.doc = "PEM-encoded PKCS#3 file with pre-generated parameters"

2370

" for the Diffie-Hellman key exchange",

2371

.group = 2 },

2372

1592

{ .name = "priority", .key = 130,

2373

1593

.arg = "STRING",

2374

1594

.doc = "GnuTLS priority string for the TLS handshake",

2379

1599

.group = 2 },

2380

1600

{ .name = "retry", .key = 132,

2381

1601

.arg = "SECONDS",

2382

.doc = "Retry interval used when denied by the Mandos server",

1602

.doc = "Retry interval used when denied by the mandos server",

2383

1603

.group = 2 },

2384

1604

{ .name = "network-hook-dir", .key = 133,

2385

1605

.arg = "DIR",

2408

1628

connect_to = arg;

2409

1629

break;

2410

1630

case 'i': /* --interface */

2411

ret_errno = argz_add_sep(&mc.interfaces, &mc.interfaces_size,

2412

arg, (int)',');

2413

if(ret_errno != 0){

2414

argp_error(state, "%s", strerror(ret_errno));

2415

}

1631

interface = arg;

2416

1632

break;

2417

1633

case 's': /* --seckey */

2418

1634

seckey = arg;

2429

1645

}

2430

1646

mc.dh_bits = (typeof(mc.dh_bits))tmpmax;

2431

1647

break;

2432

case 134: /* --dh-params */

2433

dh_params_file = arg;

2434

break;

2435

1648

case 130: /* --priority */

2436

1649

mc.priority = arg;

2437

1650

break;

2477

1690

.args_doc = "",

2478

1691

.doc = "Mandos client -- Get and decrypt"

2479

1692

" passwords from a Mandos server" };

2480

ret_errno = argp_parse(&argp, argc, argv,

2481

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

2482

switch(ret_errno){

1693

ret = argp_parse(&argp, argc, argv,

1694

ARGP_IN_ORDER | ARGP_NO_HELP, 0, NULL);

1695

switch(ret){

2483

1696

case 0:

2484

1697

break;

2485

1698

case ENOMEM:

2486

1699

default:

2487

errno = ret_errno;

1700

errno = ret;

2488

1701

perror_plus("argp_parse");

2489

1702

exitcode = EX_OSERR;

2490

1703

goto end;

2493

1706

goto end;

2494

1707

}

2495

1708

}

2496

1709

2497

1710

{

2498

1711

/* Work around Debian bug #633582:

2499

1712

<http://bugs.debian.org/633582> */

2500

1713

2501

/* Re-raise privileges */

2502

ret = raise_privileges();

2503

if(ret != 0){

2504

errno = ret;

2505

perror_plus("Failed to raise privileges");

1714

/* Re-raise priviliges */

1715

errno = 0;

1716

ret = seteuid(0);

1717

if(ret == -1){

1718

perror_plus("seteuid");

2506

1719

} else {

2507

1720

struct stat st;

2508

1721

2523

1736

}

2524

1737

}

2525

1738

}

2526

close(seckey_fd);

1739

TEMP_FAILURE_RETRY(close(seckey_fd));

2527

1740

}

2528

1741

}

2529

1742

2530

1743

if(strcmp(pubkey, PATHDIR "/" PUBKEY) == 0){

2531

1744

int pubkey_fd = open(pubkey, O_RDONLY);

2532

1745

if(pubkey_fd == -1){

2544

1757

}

2545

1758

}

2546

1759

}

2547

close(pubkey_fd);

2548

}

2549

}

2550

2551

if(dh_params_file != NULL

2552

and strcmp(dh_params_file, PATHDIR "/dhparams.pem" ) == 0){

2553

int dhparams_fd = open(dh_params_file, O_RDONLY);

2554

if(dhparams_fd == -1){

2555

perror_plus("open");

2556

} else {

2557

ret = (int)TEMP_FAILURE_RETRY(fstat(dhparams_fd, &st));

2558

if(ret == -1){

2559

perror_plus("fstat");

2560

} else {

2561

if(S_ISREG(st.st_mode)

2562

and st.st_uid == 0 and st.st_gid == 0){

2563

ret = fchown(dhparams_fd, uid, gid);

2564

if(ret == -1){

2565

perror_plus("fchown");

2566

}

2567

}

2568

}

2569

close(dhparams_fd);

2570

}

2571

}

2572

1760

TEMP_FAILURE_RETRY(close(pubkey_fd));

1761

}

1762

}

1763

2573

1764

/* Lower privileges */

2574

ret = lower_privileges();

2575

if(ret != 0){

2576

errno = ret;

2577

perror_plus("Failed to lower privileges");

2578

}

2579

}

2580

}

2581

2582

/* Remove invalid interface names (except "none") */

2583

{

2584

char *interface = NULL;

2585

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2586

interface))){

2587

if(strcmp(interface, "none") != 0

2588

and if_nametoindex(interface) == 0){

2589

if(interface[0] != '\0'){

2590

fprintf_plus(stderr, "Not using nonexisting interface"

2591

" \"%s\"\n", interface);

2592

}

2593

argz_delete(&mc.interfaces, &mc.interfaces_size, interface);

2594

interface = NULL;

1765

errno = 0;

1766

ret = seteuid(uid);

1767

if(ret == -1){

1768

perror_plus("seteuid");

2595

1769

}

2596

1770

}

2597

1771

}

2598

1772

2599

1773

/* Run network hooks */

2600

{

2601

if(mc.interfaces != NULL){

2602

interfaces_hooks = malloc(mc.interfaces_size);

2603

if(interfaces_hooks == NULL){

2604

perror_plus("malloc");

2605

goto end;

2606

}

2607

memcpy(interfaces_hooks, mc.interfaces, mc.interfaces_size);

2608

argz_stringify(interfaces_hooks, mc.interfaces_size, (int)',');

2609

}

2610

run_network_hooks("start", interfaces_hooks != NULL ?

2611

interfaces_hooks : "", delay);

1774

if(not run_network_hooks("start", interface, delay)){

1775

goto end;

2612

1776

}

2613

1777

2614

1778

if(not debug){

2615

1779

avahi_set_log_function(empty_log);

2616

1780

}

2617

1781

1782

if(interface[0] == '\0'){

1783

struct dirent **direntries;

1784

/* First look for interfaces that are up */

1785

ret = scandir(sys_class_net, &direntries, up_interface,

1786

alphasort);

1787

if(ret == 0){

1788

/* No up interfaces, look for any good interfaces */

1789

free(direntries);

1790

ret = scandir(sys_class_net, &direntries, good_interface,

1791

alphasort);

1792

}

1793

if(ret >= 1){

1794

/* Pick the first interface returned */

1795

interface = strdup(direntries[0]->d_name);

1796

if(debug){

1797

fprintf_plus(stderr, "Using interface \"%s\"\n", interface);

1798

}

1799

if(interface == NULL){

1800

perror_plus("malloc");

1801

free(direntries);

1802

exitcode = EXIT_FAILURE;

1803

goto end;

1804

}

1805

free(direntries);

1806

} else {

1807

free(direntries);

1808

fprintf_plus(stderr, "Could not find a network interface\n");

1809

exitcode = EXIT_FAILURE;

1810

goto end;

1811

}

1812

}

1813

2618

1814

/* Initialize Avahi early so avahi_simple_poll_quit() can be called

2619

1815

from the signal handler */

2620

1816

/* Initialize the pseudo-RNG for Avahi */

2621

1817

srand((unsigned int) time(NULL));

2622

simple_poll = avahi_simple_poll_new();

2623

if(simple_poll == NULL){

1818

mc.simple_poll = avahi_simple_poll_new();

1819

if(mc.simple_poll == NULL){

2624

1820

fprintf_plus(stderr,

2625

1821

"Avahi: Failed to create simple poll object.\n");

2626

1822

exitcode = EX_UNAVAILABLE;

2690

1886

}

2691

1887

}

2692

1888

2693

/* If no interfaces were specified, make a list */

2694

if(mc.interfaces == NULL){

2695

struct dirent **direntries = NULL;

2696

/* Look for any good interfaces */

2697

ret = scandir(sys_class_net, &direntries, good_interface,

2698

alphasort);

2699

if(ret >= 1){

2700

/* Add all found interfaces to interfaces list */

2701

for(int i = 0; i < ret; ++i){

2702

ret_errno = argz_add(&mc.interfaces, &mc.interfaces_size,

2703

direntries[i]->d_name);

2704

if(ret_errno != 0){

2705

errno = ret_errno;

2706

perror_plus("argz_add");

2707

free(direntries[i]);

2708

continue;

2709

}

2710

if(debug){

2711

fprintf_plus(stderr, "Will use interface \"%s\"\n",

2712

direntries[i]->d_name);

2713

}

2714

free(direntries[i]);

2715

}

2716

free(direntries);

2717

} else {

2718

if(ret == 0){

2719

free(direntries);

2720

}

2721

fprintf_plus(stderr, "Could not find a network interface\n");

2722

exitcode = EXIT_FAILURE;

2723

goto end;

2724

}

2725

}

2726

2727

/* Bring up interfaces which are down, and remove any "none"s */

2728

{

2729

char *interface = NULL;

2730

while((interface = argz_next(mc.interfaces, mc.interfaces_size,

2731

interface))){

2732

/* If interface name is "none", stop bringing up interfaces.

2733

Also remove all instances of "none" from the list */

2734

if(strcmp(interface, "none") == 0){

2735

argz_delete(&mc.interfaces, &mc.interfaces_size,

2736

interface);

2737

interface = NULL;

2738

while((interface = argz_next(mc.interfaces,

2739

mc.interfaces_size, interface))){

2740

if(strcmp(interface, "none") == 0){

2741

argz_delete(&mc.interfaces, &mc.interfaces_size,

2742

interface);

2743

interface = NULL;

1889

/* If the interface is down, bring it up */

1890

if(strcmp(interface, "none") != 0){

1891

if_index = (AvahiIfIndex) if_nametoindex(interface);

1892

if(if_index == 0){

1893

fprintf_plus(stderr, "No such interface: \"%s\"\n", interface);

1894

exitcode = EX_UNAVAILABLE;

1895

goto end;

1896

}

1897

1898

if(quit_now){

1899

goto end;

1900

}

1901

1902

/* Re-raise priviliges */

1903

errno = 0;

1904

ret = seteuid(0);

1905

if(ret == -1){

1906

perror_plus("seteuid");

1907

}

1908

1909

#ifdef __linux__

1910

/* Lower kernel loglevel to KERN_NOTICE to avoid KERN_INFO

1911

messages about the network interface to mess up the prompt */

1912

ret = klogctl(8, NULL, 5);

1913

bool restore_loglevel = true;

1914

if(ret == -1){

1915

restore_loglevel = false;

1916

perror_plus("klogctl");

1917

}

1918

#endif /* __linux__ */

1919

1920

sd = socket(PF_INET6, SOCK_DGRAM, IPPROTO_IP);

1921

if(sd < 0){

1922

perror_plus("socket");

1923

exitcode = EX_OSERR;

1924

#ifdef __linux__

1925

if(restore_loglevel){

1926

ret = klogctl(7, NULL, 0);

1927

if(ret == -1){

1928

perror_plus("klogctl");

1929

}

1930

}

1931

#endif /* __linux__ */

1932

/* Lower privileges */

1933

errno = 0;

1934

ret = seteuid(uid);

1935

if(ret == -1){

1936

perror_plus("seteuid");

1937

}

1938

goto end;

1939

}

1940

strcpy(network.ifr_name, interface);

1941

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1942

if(ret == -1){

1943

perror_plus("ioctl SIOCGIFFLAGS");

1944

#ifdef __linux__

1945

if(restore_loglevel){

1946

ret = klogctl(7, NULL, 0);

1947

if(ret == -1){

1948

perror_plus("klogctl");

1949

}

1950

}

1951

#endif /* __linux__ */

1952

exitcode = EX_OSERR;

1953

/* Lower privileges */

1954

errno = 0;

1955

ret = seteuid(uid);

1956

if(ret == -1){

1957

perror_plus("seteuid");

1958

}

1959

goto end;

1960

}

1961

if((network.ifr_flags & IFF_UP) == 0){

1962

network.ifr_flags |= IFF_UP;

1963

take_down_interface = true;

1964

ret = ioctl(sd, SIOCSIFFLAGS, &network);

1965

if(ret == -1){

1966

take_down_interface = false;

1967

perror_plus("ioctl SIOCSIFFLAGS +IFF_UP");

1968

exitcode = EX_OSERR;

1969

#ifdef __linux__

1970

if(restore_loglevel){

1971

ret = klogctl(7, NULL, 0);

1972

if(ret == -1){

1973

perror_plus("klogctl");

2744

1974

}

2745

1975

}

1976

#endif /* __linux__ */

1977

/* Lower privileges */

1978

errno = 0;

1979

ret = seteuid(uid);

1980

if(ret == -1){

1981

perror_plus("seteuid");

1982

}

1983

goto end;

1984

}

1985

}

1986

/* Sleep checking until interface is running.

1987

Check every 0.25s, up to total time of delay */

1988

for(int i=0; i < delay * 4; i++){

1989

ret = ioctl(sd, SIOCGIFFLAGS, &network);

1990

if(ret == -1){

1991

perror_plus("ioctl SIOCGIFFLAGS");

1992

} else if(network.ifr_flags & IFF_RUNNING){

2746

1993

break;

2747

1994

}

2748

bool interface_was_up = interface_is_up(interface);

2749

errno = bring_up_interface(interface, delay);

2750

if(not interface_was_up){

2751

if(errno != 0){

2752

fprintf_plus(stderr, "Failed to bring up interface \"%s\":"

2753

" %s\n", interface, strerror(errno));

2754

} else {

2755

errno = argz_add(&interfaces_to_take_down,

2756

&interfaces_to_take_down_size,

2757

interface);

2758

if(errno != 0){

2759

perror_plus("argz_add");

2760

}

2761

}

2762

}

2763

}

2764

if(debug and (interfaces_to_take_down == NULL)){

2765

fprintf_plus(stderr, "No interfaces were brought up\n");

2766

}

2767

}

2768

2769

/* If we only got one interface, explicitly use only that one */

2770

if(argz_count(mc.interfaces, mc.interfaces_size) == 1){

2771

if(debug){

2772

fprintf_plus(stderr, "Using only interface \"%s\"\n",

2773

mc.interfaces);

2774

}

2775

if_index = (AvahiIfIndex)if_nametoindex(mc.interfaces);

1995

struct timespec sleeptime = { .tv_nsec = 250000000 };

1996

ret = nanosleep(&sleeptime, NULL);

1997

if(ret == -1 and errno != EINTR){

1998

perror_plus("nanosleep");

1999

}

2000

}

2001

if(not take_down_interface){

2002

/* We won't need the socket anymore */

2003

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2004

if(ret == -1){

2005

perror_plus("close");

2006

}

2007

}

2008

#ifdef __linux__

2009

if(restore_loglevel){

2010

/* Restores kernel loglevel to default */

2011

ret = klogctl(7, NULL, 0);

2012

if(ret == -1){

2013

perror_plus("klogctl");

2014

}

2015

}

2016

#endif /* __linux__ */

2017

/* Lower privileges */

2018

errno = 0;

2019

/* Lower privileges */

2020

ret = seteuid(uid);

2021

if(ret == -1){

2022

perror_plus("seteuid");

2023

}

2776

2024

}

2777

2025

2778

2026

if(quit_now){

2779

2027

goto end;

2780

2028

}

2781

2029

2782

ret = init_gnutls_global(pubkey, seckey, dh_params_file, &mc);

2030

ret = init_gnutls_global(pubkey, seckey);

2783

2031

if(ret == -1){

2784

2032

fprintf_plus(stderr, "init_gnutls_global failed\n");

2785

2033

exitcode = EX_UNAVAILABLE;

2792

2040

goto end;

2793

2041

}

2794

2042

2795

/* Try /run/tmp before /tmp */

2796

tempdir = mkdtemp(run_tempdir);

2797

if(tempdir == NULL and errno == ENOENT){

2798

if(debug){

2799

fprintf_plus(stderr, "Tempdir %s did not work, trying %s\n",

2800

run_tempdir, old_tempdir);

2801

}

2802

tempdir = mkdtemp(old_tempdir);

2803

}

2804

if(tempdir == NULL){

2043

if(mkdtemp(tempdir) == NULL){

2805

2044

perror_plus("mkdtemp");

2806

2045

goto end;

2807

2046

}

2047

tempdir_created = true;

2808

2048

2809

2049

if(quit_now){

2810

2050

goto end;

2811

2051

}

2812

2052

2813

if(not init_gpgme(pubkey, seckey, tempdir, &mc)){

2053

if(not init_gpgme(pubkey, seckey, tempdir)){

2814

2054

fprintf_plus(stderr, "init_gpgme failed\n");

2815

2055

exitcode = EX_UNAVAILABLE;

2816

2056

goto end;

2826

2066

/* Connect directly, do not use Zeroconf */

2827

2067

/* (Mainly meant for debugging) */

2828

2068

char *address = strrchr(connect_to, ':');

2829

2830

2069

if(address == NULL){

2831

2070

fprintf_plus(stderr, "No colon in address\n");

2832

2071

exitcode = EX_USAGE;

2837

2076

goto end;

2838

2077

}

2839

2078

2840

in_port_t port;

2079

uint16_t port;

2841

2080

errno = 0;

2842

2081

tmpmax = strtoimax(address+1, &tmp, 10);

2843

2082

if(errno != 0 or tmp == address+1 or *tmp != '\0'

2844

or tmpmax != (in_port_t)tmpmax){

2083

or tmpmax != (uint16_t)tmpmax){

2845

2084

fprintf_plus(stderr, "Bad port number\n");

2846

2085

exitcode = EX_USAGE;

2847

2086

goto end;

2848

2087

}

2849

2088

2850

2089

if(quit_now){

2851

2090

goto end;

2852

2091

}

2853

2092

2854

port = (in_port_t)tmpmax;

2093

port = (uint16_t)tmpmax;

2855

2094

*address = '\0';

2856

2095

/* Colon in address indicates IPv6 */

2857

2096

int af;

2873

2112

}

2874

2113

2875

2114

while(not quit_now){

2876

ret = start_mandos_communication(address, port, if_index, af,

2877

&mc);

2115

ret = start_mandos_communication(address, port, if_index, af);

2878

2116

if(quit_now or ret == 0){

2879

2117

break;

2880

2118

}

2882

2120

fprintf_plus(stderr, "Retrying in %d seconds\n",

2883

2121

(int)retry_interval);

2884

2122

}

2885

sleep((unsigned int)retry_interval);

2123

sleep((int)retry_interval);

2886

2124

}

2887

2125

2888

if(not quit_now){

2126

if (not quit_now){

2889

2127

exitcode = EXIT_SUCCESS;

2890

2128

}

2891

2129

2906

2144

config.publish_domain = 0;

2907

2145

2908

2146

/* Allocate a new server */

2909

mc.server = avahi_server_new(avahi_simple_poll_get(simple_poll),

2910

&config, NULL, NULL, &ret);

2147

mc.server = avahi_server_new(avahi_simple_poll_get

2148

(mc.simple_poll), &config, NULL,

2149

NULL, &error);

2911

2150

2912

2151

/* Free the Avahi configuration data */

2913

2152

avahi_server_config_free(&config);

2916

2155

/* Check if creating the Avahi server object succeeded */

2917

2156

if(mc.server == NULL){

2918

2157

fprintf_plus(stderr, "Failed to create Avahi server: %s\n",

2919

avahi_strerror(ret));

2158

avahi_strerror(error));

2920

2159

exitcode = EX_UNAVAILABLE;

2921

2160

goto end;

2922

2161

}

2928

2167

/* Create the Avahi service browser */

2929

2168

sb = avahi_s_service_browser_new(mc.server, if_index,

2930

2169

AVAHI_PROTO_UNSPEC, "_mandos._tcp",

2931

NULL, 0, browse_callback,

2932

(void *)&mc);

2170

NULL, 0, browse_callback, NULL);

2933

2171

if(sb == NULL){

2934

2172

fprintf_plus(stderr, "Failed to create service browser: %s\n",

2935

2173

avahi_strerror(avahi_server_errno(mc.server)));

2946

2184

if(debug){

2947

2185

fprintf_plus(stderr, "Starting Avahi loop search\n");

2948

2186

}

2949

2950

ret = avahi_loop_with_timeout(simple_poll,

2951

(int)(retry_interval * 1000), &mc);

2187

2188

ret = avahi_loop_with_timeout(mc.simple_poll,

2189

(int)(retry_interval * 1000));

2952

2190

if(debug){

2953

2191

fprintf_plus(stderr, "avahi_loop_with_timeout exited %s\n",

2954

2192

(ret == 0) ? "successfully" : "with error");

2961

2199

}

2962

2200

2963

2201

/* Cleanup things */

2964

free(mc.interfaces);

2965

2966

2202

if(sb != NULL)

2967

2203

avahi_s_service_browser_free(sb);

2968

2204

2969

2205

if(mc.server != NULL)

2970

2206

avahi_server_free(mc.server);

2971

2207

2972

if(simple_poll != NULL)

2973

avahi_simple_poll_free(simple_poll);

2208

if(mc.simple_poll != NULL)

2209

avahi_simple_poll_free(mc.simple_poll);

2974

2210

2975

2211

if(gnutls_initialized){

2976

2212

gnutls_certificate_free_credentials(mc.cred);

2213

gnutls_global_deinit();

2977

2214

gnutls_dh_params_deinit(mc.dh_params);

2978

2215

}

2979

2216

2987

2224

mc.current_server->prev->next = NULL;

2988

2225

while(mc.current_server != NULL){

2989

2226

server *next = mc.current_server->next;

2990

#ifdef __GNUC__

2991

#pragma GCC diagnostic push

2992

#pragma GCC diagnostic ignored "-Wcast-qual"

2993

#endif

2994

free((char *)(mc.current_server->ip));

2995

#ifdef __GNUC__

2996

#pragma GCC diagnostic pop

2997

#endif

2998

2227

free(mc.current_server);

2999

2228

mc.current_server = next;

3000

2229

}

3001

2230

}

3002

2231

3003

/* Re-raise privileges */

2232

/* Run network hooks */

2233

run_network_hooks("stop", interface, delay);

2234

2235

/* Re-raise priviliges */

3004

2236

{

3005

ret = raise_privileges();

3006

if(ret != 0){

3007

errno = ret;

3008

perror_plus("Failed to raise privileges");

3009

} else {

3010

3011

/* Run network hooks */

3012

run_network_hooks("stop", interfaces_hooks != NULL ?

3013

interfaces_hooks : "", delay);

3014

3015

/* Take down the network interfaces which were brought up */

3016

{

3017

char *interface = NULL;

3018

while((interface=argz_next(interfaces_to_take_down,

3019

interfaces_to_take_down_size,

3020

interface))){

3021

ret = take_down_interface(interface);

3022

if(ret != 0){

3023

errno = ret;

3024

perror_plus("Failed to take down interface");

3025

}

3026

}

3027

if(debug and (interfaces_to_take_down == NULL)){

3028

fprintf_plus(stderr, "No interfaces needed to be taken"

3029

" down\n");

3030

}

3031

}

2237

errno = 0;

2238

ret = seteuid(0);

2239

if(ret == -1){

2240

perror_plus("seteuid");

3032

2241

}

3033

2242

3034

ret = lower_privileges_permanently();

3035

if(ret != 0){

3036

errno = ret;

3037

perror_plus("Failed to lower privileges permanently");

2243

/* Take down the network interface */

2244

if(take_down_interface and geteuid() == 0){

2245

ret = ioctl(sd, SIOCGIFFLAGS, &network);

2246

if(ret == -1){

2247

perror_plus("ioctl SIOCGIFFLAGS");

2248

} else if(network.ifr_flags & IFF_UP){

2249

network.ifr_flags &= ~(short)IFF_UP; /* clear flag */

2250

ret = ioctl(sd, SIOCSIFFLAGS, &network);

2251

if(ret == -1){

2252

perror_plus("ioctl SIOCSIFFLAGS -IFF_UP");

2253

}

2254

}

2255

ret = (int)TEMP_FAILURE_RETRY(close(sd));

2256

if(ret == -1){

2257

perror_plus("close");

2258

}

3038

2259

}

3039

2260

}

3040

3041

free(interfaces_to_take_down);

3042

free(interfaces_hooks);

3043

3044

void clean_dir_at(int base, const char * const dirname,

3045

uintmax_t level){

2261

/* Lower privileges permanently */

2262

errno = 0;

2263

ret = setuid(uid);

2264

if(ret == -1){

2265

perror_plus("setuid");

2266

}

2267

2268

/* Removes the GPGME temp directory and all files inside */

2269

if(tempdir_created){

3046

2270

struct dirent **direntries = NULL;

3047

int dret;

3048

int dir_fd = (int)TEMP_FAILURE_RETRY(openat(base, dirname,

3049

O_RDONLY

3050

| O_NOFOLLOW

3051

| O_DIRECTORY

3052

| O_PATH));

3053

if(dir_fd == -1){

3054

perror_plus("open");

3055

}

3056

int numentries = scandirat(dir_fd, ".", &direntries,

3057

notdotentries, alphasort);

3058

if(numentries >= 0){

2271

struct dirent *direntry = NULL;

2272

int numentries = scandir(tempdir, &direntries, notdotentries,

2273

alphasort);

2274

if (numentries > 0){

3059

2275

for(int i = 0; i < numentries; i++){

3060

if(debug){

3061

fprintf_plus(stderr, "Unlinking \"%s/%s\"\n",

3062

dirname, direntries[i]->d_name);

3063

}

3064

dret = unlinkat(dir_fd, direntries[i]->d_name, 0);

3065

if(dret == -1){

3066

if(errno == EISDIR){

3067

dret = unlinkat(dir_fd, direntries[i]->d_name,

3068

AT_REMOVEDIR);

3069

}

3070

if((dret == -1) and (errno == ENOTEMPTY)

3071

and (strcmp(direntries[i]->d_name, "private-keys-v1.d")

3072

== 0) and (level == 0)){

3073

/* Recurse only in this special case */

3074

clean_dir_at(dir_fd, direntries[i]->d_name, level+1);

3075

dret = 0;

3076

}

3077

if(dret == -1){

3078

fprintf_plus(stderr, "unlink(\"%s/%s\"): %s\n", dirname,

3079

direntries[i]->d_name, strerror(errno));

3080

}

3081

}

3082

free(direntries[i]);

3083

}

3084

3085

/* need to clean even if 0 because man page doesn't specify */

3086

free(direntries);

3087

if(numentries == -1){

3088

perror_plus("scandirat");

3089

}

3090

dret = unlinkat(base, dirname, AT_REMOVEDIR);

3091

if(dret == -1 and errno != ENOENT){

3092

perror_plus("rmdir");

3093

}

3094

} else {

3095

perror_plus("scandirat");

3096

}

3097

close(dir_fd);

3098

}

3099

3100

/* Removes the GPGME temp directory and all files inside */

3101

if(tempdir != NULL){

3102

clean_dir_at(-1, tempdir, 0);

2276

direntry = direntries[i];

2277

char *fullname = NULL;

2278

ret = asprintf(&fullname, "%s/%s", tempdir,

2279

direntry->d_name);

2280

if(ret < 0){

2281

perror_plus("asprintf");

2282

continue;

2283

}

2284

ret = remove(fullname);

2285

if(ret == -1){

2286

fprintf_plus(stderr, "remove(\"%s\"): %s\n", fullname,

2287

strerror(errno));

2288

}

2289

free(fullname);

2290

}

2291

}

2292

2293

/* need to clean even if 0 because man page doesn't specify */

2294

free(direntries);

2295

if (numentries == -1){

2296

perror_plus("scandir");

2297

}

2298

ret = rmdir(tempdir);

2299

if(ret == -1 and errno != ENOENT){

2300

perror_plus("rmdir");

2301

}

3103

2302

}

3104

2303

3105

2304

if(quit_now){